docstr: >>> alternatives = [{"transcript": "one two three", "confidence": 0.42899391}, {"transcript": "1 2", "confidence": 0.49585345}]
  >>> OutputParser.find_best_hypothesis(alternatives)
  {'transcript': 'one two three', 'confidence': 0.42899391}
  
  >>> alternatives = [{"confidence": 0.49585345}]
  >>> OutputParser.find_best_hypothesis(alternatives)
  Traceback (most recent call last):
    ...
  speech_recognition.exceptions.UnknownValueError
docstr_tok: [">",">",">","alternatives","=","[","{","``","transcript","''",":","``","one","two","three","''",",","``","confidence","''",":","0.42899391","}",",","{","``","transcript","''",":","``","1","2","''",",","``","confidence","''",":","0.49585345","}","]",">",">",">","OutputParser.find_best_hypothesis","(","alternatives",")","{","'transcript","'",":","'one","two","three","'",",","'confidence","'",":","0.42899391","}",">",">",">","alternatives","=","[","{","``","confidence","''",":","0.49585345","}","]",">",">",">","OutputParser.find_best_hypothesis","(","alternatives",")","Traceback","(","most","recent","call","last",")",":","...","speech_recognition.exceptions.UnknownValueError"]
code: def find_best_hypothesis(
      alternatives: list[Alternative],
  ) -> Alternative:
      """
      >>> alternatives = [{"transcript": "one two three", "confidence": 0.42899391}, {"transcript": "1 2", "confidence": 0.49585345}]
      >>> OutputParser.find_best_hypothesis(alternatives)
      {'transcript': 'one two three', 'confidence': 0.42899391}
  
      >>> alternatives = [{"confidence": 0.49585345}]
      >>> OutputParser.find_best_hypothesis(alternatives)
      Traceback (most recent call last):
        ...
      speech_recognition.exceptions.UnknownValueError
      """
      if "confidence" in alternatives:
          # BUG: actual_result["alternative"] (=alternatives) is list, not dict
          # return alternative with highest confidence score
          best_hypothesis: Alternative = max(
              alternatives,
              key=lambda alternative: alternative["confidence"],
          )
      else:
          # when there is no confidence available, we arbitrarily choose the first hypothesis.
          best_hypothesis: Alternative = alternatives[0]
      if "transcript" not in best_hypothesis:
          raise UnknownValueError()
      return best_hypothesis
  
imports: from __future__ import annotations
  import json
  from typing import Dict, Literal, TypedDict
  from urllib.error import HTTPError, URLError
  from urllib.parse import urlencode
  from urllib.request import Request, urlopen
  from typing_extensions import NotRequired
  from speech_recognition.audio import AudioData
  from speech_recognition.exceptions import RequestError, UnknownValueError
label_desc: Use image node_id 4 for calling the OutputParser obj's underlying member method code with example usage: obj.find_best_hypothesis(alternatives) and returns: best_hypothesis